I have suspected for a while that my left leg is not as strong as my right. The other day I had the chance to try out a bike computrainer. I was surprised that my left leg was contributing only 40-45% of total power - a larger imbalance than I would have thought. What is a usual range of imbalance? (+- 2%?)

Has anyone else had experience with unequal leg strength? Have you done anything about it e.g. more one-legged type strength exercises on the weak leg? Is it really a problem?

FWIW I do get some left hamstring pain now-and-then (I suspect hamstring compensating for weak glute), and have checked that my legs are of equal length.

From memory, my old PT used to say any more than 10% muscle imbalances greatly increase the risk of injury. He was referring to opposing muscle sets, like chest and back, but I think that would apply for other areas too.

I'm surprised at such an imbalance. It's not like you use your right leg more often than the right. Maybe a PT or physio could give you some exercises to balance it. 1 legged bodyweight squats would certainly work, but they're pretty intense. Not sure what else.

UpDownUp wrote:I have suspected for a while that my left leg is not as strong as my right. The other day I had the chance to try out a bike computrainer. I was surprised that my left leg was contributing only 40-45% of total power - a larger imbalance than I would have thought. What is a usual range of imbalance? (+- 2%?)

It depends on how hard you were riding. It is pretty common at lower power levels that the difference be reasonably large as measured by such devices and a 45-55 split is not uncommon. But as power goes up, usually it evens out a lot more.

Bear in mind that the Computrainer spin scan is only estimating the left-right balance. It can't really know given the cranks are physically connected and cannot determine whether an imbalance is due to one leg pushing down with less force, or the opposing leg resisting more or a combination. They are considerably different scenarios which might imply taking totally different actions (or no action at all) and hence SS data must be taken with a large grain of salt.

UpDownUp wrote:Has anyone else had experience with unequal leg strength? Have you done anything about it e.g. more one-legged type strength exercises on the weak leg?

I had a below knee amputation 5 years ago and have a pretty large imbalance. I still managed to produce more sustainable power than I did before my amputation.

Strength is not a limiter to endurance cycling power. It's an aerobic sport.

UpDownUp wrote:Is it really a problem?

No, unless it's due to a poor bike fit. Some L-R imbalance is normal and it's way over rated as a problem.

UpDownUp wrote:FWIW I do get some left hamstring pain now-and-then (I suspect hamstring compensating for weak glute), and have checked that my legs are of equal length.

I would suggest considering a bike fit, perhaps get a specialist to check it out. Hamstring strain can be a sign of the saddle being a little too high. But it might be other things too, like cleat placement.

There are many factors that can come into play in your situation. The possible solutions vary from being quite simple to complex. If you came into my clinic (chiro), after taking your history I would do a functional evaluation. As long as there is no gross anomaly or disease process, the solution is generally multi-factorial but simple.

Do the one leg pedaling exercise regularly and soon you will make it even. 2-3 sets per session, 20 sec with one leg pedaling, the other one is resting off the pedal, than change to another leg, than 30 sec the same and then 1 min the same, this is 1 set. Rest between sets not less than 20 mins. That will also help you to improve the right circular pedaling. It helped me a lot.

I've been dealing with really bad knee issues during longer distance cycling, especially in my left knee. After riding around 800km over the past couple of weeks I have noticed that my right leg, in particular my calf, is significantly larger than my left leg. Now I have been experiencing more issues with my right knee after 2 weeks of pain in my left knee.. so year, muscular imbalance really sucks. I've had a professional bike fit done and have also seen a podiatrist with minimal benefit so-far. I'll have to chase it up when I get back to Oz.

Dayrider wrote:Do the one leg pedaling exercise regularly and soon you will make it even. 2-3 sets per session, 20 sec with one leg pedaling, the other one is resting off the pedal, than change to another leg, than 30 sec the same and then 1 min the same, this is 1 set. Rest between sets not less than 20 mins. That will also help you to improve the right circular pedaling. It helped me a lot.

elStado wrote:I've been dealing with really bad knee issues during longer distance cycling, especially in my left knee. After riding around 800km over the past couple of weeks I have noticed that my right leg, in particular my calf, is significantly larger than my left leg. Now I have been experiencing more issues with my right knee after 2 weeks of pain in my left knee.. so year, muscular imbalance really sucks. I've had a professional bike fit done and have also seen a podiatrist with minimal benefit so-far. I'll have to chase it up when I get back to Oz.

Is that more riding that you are used to?

One of the most common causes of acute injury in cycling is a large increase in training load. It may not have mattered what a specialist fitter had done. If you try to ramp up workload too much too quickly, you'll significantly increase probability of causing injury.

Whenever you change bike set up, you also need to allow for some adaptation time before going hard, or doing more than normal. How much time depends on the nature of the changes.

elStado wrote:I've been dealing with really bad knee issues during longer distance cycling, especially in my left knee. After riding around 800km over the past couple of weeks I have noticed that my right leg, in particular my calf, is significantly larger than my left leg. Now I have been experiencing more issues with my right knee after 2 weeks of pain in my left knee.. so year, muscular imbalance really sucks. I've had a professional bike fit done and have also seen a podiatrist with minimal benefit so-far. I'll have to chase it up when I get back to Oz.

Is that more riding that you are used to?

One of the most common causes of acute injury in cycling is a large increase in training load. It may not have mattered what a specialist fitter had done. If you try to ramp up workload too much too quickly, you'll significantly increase probability of causing injury.

Whenever you change bike set up, you also need to allow for some adaptation time before going hard, or doing more than normal. How much time depends on the nature of the changes.

Yeah it is more than I am used to. I usually ride around 20km per ride, so going to 70-85km per day with 30kg of touring bike+gear was probably asking for trouble. I have been mostly off the bike for the past week, aside from the occasional 10km leisurely ride to a pub for a beer, so that my knees have a chance to rest and heal a bit. I need to go see someone and get it looked into, as well as gradually building up my km over a longer period of time..

In my racing days I did special drills to exercise the weaker leg and even out my pedal stroke.

Your sore knees are likely the result of pedal mashing. As I've advised previously, the VWR is not sufficiently low geared. A 22x32 low gear is required for loaded touring in hilly country. It's also a good idea to use a computer with cadence to ensure your cadence doesn't drop as you tire. Take this advice from someone who has much experience with sore knees and has learned how to avoid them (the hard way).

elStado wrote:Yeah it is more than I am used to. I usually ride around 20km per ride, so going to 70-85km per day with 30kg of touring bike+gear was probably asking for trouble. I have been mostly off the bike for the past week, aside from the occasional 10km leisurely ride to a pub for a beer, so that my knees have a chance to rest and heal a bit. I need to go see someone and get it looked into, as well as gradually building up my km over a longer period of time..

Take Voltaren Rapid 25, available over the counter from pharmacies, or rub Voltaren Emugel on the knee. It will quickly reduce the inflammation. You should always have some in your medicine kit when touring, as you never know when you may sustain a muscular injury.

elStado wrote:Yeah it is more than I am used to. I usually ride around 20km per ride, so going to 70-85km per day with 30kg of touring bike+gear was probably asking for trouble. I have been mostly off the bike for the past week, aside from the occasional 10km leisurely ride to a pub for a beer, so that my knees have a chance to rest and heal a bit. I need to go see someone and get it looked into, as well as gradually building up my km over a longer period of time..

Take Voltaren Rapid 25, available over the counter from pharmacies, or rub Voltaren Emugel on the knee. It will quickly reduce the inflammation. You should always have some in your medicine kit when touring, as you never know when you may sustain a muscular injury.

Yup, I was carrying a small tube of Voltaren Emugel in the medikit. I also had a roll of kinesiology tape to hold my knee together and reduce pain should discomfort start to occur as I was riding (as instructed by my podiatrist). It helped, but not that much.